Internal combustion engine



April 13, 1937.

A. RENNER Filed Feb. 24, 1933 2 Sheets-Sheet 1 a cYUNQERIO 2.6

25 l4 l1 FUEL SUPPLY 7:! 1s

I i 56 51. :Plg- I9 O lb COMPRESSED 47 5O 56 AIR SUPPLY l I ll 51 l5 45 4e I4 44- COMPRESSE 4a u DRIVEN FROM AIR SUPPLY CRANK SHAFT lnvento Alfred Refine)?" H is Attor'r'aeg.

April 13, 1937. A. RENNER 2,077,185

INTERNAL COMBUSTION ENGINE Filed Feb. 24, 1933 2 Sheets-Sheet 2 Fig. 2.

COM/ 17E E 4/1? 6UP Y Inventor: Alfred Renner:

(Ex/MAW His ttorne Patented Apr. 13, 1937 UNITED STATES INTERNAL COMBUSTION ENGINE Alfred Renner, Berlin-Tegel, Germany, assignor to General Electric Company, a corporation of New York Application February 24, 1933, Serial No. 658,428 In Germany March 12, 1932 8 Claims. (CI. 60-16) The present invention. relates to internal combustion engines, more particularly of the type in which fuel is supplied to the cylinder or cylinders of the engine by means including a pump having a piston operated by a cam shaft driven from the crank shaft of the engine. The pump is usually provided with a suction valve and a relief valve. The opening of these valves determines the effective stroke of the pump, that is, the part of the stroke during which fuel is being supplied to the cylinder or cylinders. The starting of internal combustion engines of larger size is usually accomplished by supplying compressed air to the cylinder or cylinders. This is effected by the provision of a starting valve operated from the cam shaft. Internal combustion engineswhich are operated in both directions of rotation are provided with two sets of cams, one set for the operation in one direction of rotation and another set for the operation in the opposite direction. To reverse these engines the plunger of the fuel pump is removed from its cam, the cam shaft or cam holder is moved axially, and the plunger or a member connected to the plung- 5 er brought into engagement with a cam for operating the engine in the opposite direction.

One object of my invention is to. provide an improved construction and arrangement for op- -erating a valve such as the fuel supply or the relief valve to control the efiective stroke of the pump.

Another object of my invention is to provide an improved arrangement for reversing the engine.

A still further object of my invention is to provide an improved arrangement for starting the engine.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawings.

In the drawings I have shown a sectional view, partly diagrammatic, of an internal combustion engine embodying my invention. Fig. 1 illustrates the starting mechanism at rest; and Figs.

2 and 3 illustrate two operating positions of a control or, auxiliary valve, of the starting mechanism.

The engine comprises a cylinder l0 with'a piston ll therein. Fuel is supplied to the engine by means including a pump l2 having a plunger I3 operated by a cam l4 fastened to a cam shaft or holder IS. The lower portion of the plunger "5 I3 is reinforced to form a block I 6 having a slot l1 and carrying at its lower end a roller l8 adjacent the cam M. The plunger I3 is biased in the downward direction, that is, towards the cam H by a spring l9 between the block l6 and a wall 20 of the engine frame; Fuel is conducted to a pump or compression chamber 2| by a conduit 22 and from the pump chamber to the cylinder by means of a conduit 23. The fuel supply and regulating means include three valves for fixing the injection stroke of the pump, that is, the motion of the piston during which fuel is supplied to the cylinder. A suction or check valve 24 provided in conduit 22 opens during the downward or suction stroke of the plunger l3 to permit fuel to flow into the chamber 2|, and closes as soon as the plunger moves upward, that is, during the compression and injection stroke. A second valve 25 is provided between the chamber 2! and the conduit 23. This valve is a pressure valve and includes a spring 26 for biasing from the compression chamber 2! through the conduit 23 to the cylinder. The opening of the relief valve causes a sudden pressure drop in the compression chamber and thus permits the valve 25 to close under action of the biasing spring 28. V

The arrangement so far described is typical of any kind of internal combustion engines in which liquid fuel is supplied under pressure to the combustion cylinder. According to my invention I provide means for operating one of the valves directly from the plunger of the fuel pump. In the present instance I have shown an arrangement in which the relief valve is opened as soon as the plunger l3 reaches a certain position during the injection stroke. In the embodiment illustrated in the drawings one end of a fulcrumed lever. 29 "enters the slot II in the block l6 to form in substance a pivotal connection therewith. A lost motion connection 30 is provided'between the relief valve 21 and the lever 29. This lost motion connection comprises a spring 3| surrounding the stem of valvew21 with its upper. end bearing against a fixed member 32 and its lower end bearing against an abutment of the stem for biasing the valve 21 towards its seat. Surrounding the lower end of member 32 is a cylindrical member 34 which has a bottom portion pivoted to an intermediate point 35 of the lever 29. During the injection stroke of the pump the right- 5 hand end of the lever 29 is moved upward, to the effect that at a certainpcsition of the pump plunger the bottom portion of member 34 engages the abutment of the valve stem and moves the valve 21 away from its seat. It will readily be seen that the lost motion in this case is defined by the clearance between the abutment of the stem of valve 21 and the bottom portion of member 34. The operation of the relief valve directly from the plunger of the pump is advantageous in that it permits a compact construction of the engine. The cam shaft becomes shorter in that no special cams for actuating the relief valve are required. In addition, the arrangement permits an easy adjustment of the relief valve. In the present instance I have shown a fulcrum for the lever 29 which comprises a shaft 36 and an eccentric 31 on shaft 36 for supporting the lever. With this arrangement adjustment of the relief valve is accomplished by turning the eccentric 31 whereby the clearance between the member 34 and the abutment of the valve may be modified. The shaft 36 together with the eccentric 31 accordingly form a means for regulating the engine and may be termed a regulating shaft. During operation, turning of the regulating shaft causes a retardation or advancing of the opening of the relief valve, resulting in an increased and respectively decreased length of the effective injection stroke.

The removing of the roller l8 of the pump plunger from its cam for reversing the engine is accomplished in accordance with my invention by turning the lever 29 in counterclockwise direction about its eccentric. To this end I provide a shaft 38 which may be termed a maneuvering shaft and a cam 39 fastened thereto. In the drawings I have shown the cam in a position for normal operation of the engine. For reversing the engine the maneuvering shaft 38 is turned in the direction k indicated by an arrow whereby the cam 39 which moved away a certain distance from the cam l4,

the cam shaft or cam holder |5 may be moved axially until anothercam |4a reaches a position underneath the roller l8. Thereafter the maneuvering shaft is turned back into the position shown in the drawings whereby the plunger is forced downward by the action of the spring l9 and the roller It comes into engagement with the operating cam I40. The maneuvering shaft with the cam 39 serves also for adjusting the play between the roller l8 and the cams l4 and Ila respectively. As will be seen from .the drawings, the roller l8 does not actually engage the narrow portion or low section a of the cam but forms a clearance therewith. This clearance or play which is in the order of one thirty-secondth of an inch can be adjusted, inthe present instance, increased; by turning the maneuvering shaft 38in the direction indicated by an arrow. The cam 39 forms a stop for the roller 49 and through the lever 29 a means for limiting the The lever turns about the eccentric and.

movement of the roller |8 and the block l5 towards the cam M or |4a.

Another important function of the lever 29 and the maneuvering shaft 38 with its cam 39 is to operate the starting valve or valves of the engine. As set forth above, large size engines of this kind may be started by supplying compressed air to the cylinder or cylinders. In the present instance-I have shown a valve 4| having a valve member 42 near the cylinder, and defining a channel 43 for conducting compressed air to the cylinder. The valve member 42 is fastened to a stem 44 which has an upper portion provided with a piston 45 and an intermediate portion provided with a guide block 46. The valve is biased towards its seat by a spring 41 between the piston 45 and a L portion 48 of the valve casing. A cover 49 for the valve casing defines a chamber 49a above the piston 45. The valve is opened by means of compressed air or like actuating fluid supplied to said chamber. The means for supplying compressed air comprises an auxiliary valve 50 having a casing 5| with a movable valve member 52 therein. The valve member 52 slides in the casing and has an intermediate reduced portion 53 and a groove 54. A channel 55 in the casing wall communicates with an annular space 55 in the lower part of the casing. This annular space is connected to an air supply conduit including a valve 51 for conducting compressed air or similar gas to the valve. The valve member 52 is biased downwardly by means of a spring 58 surrounding the valve member 52 in the enlarged space 55., A conduit 50 is connected to the space 49a at one end and opens into the casing 5| near its upper end.

In Fig. 1 the valve member is illustrated as being in its lowermost and inoperative position. This position is obtained after valve 51 is closed and the pressure in the space 55 has fallen below the pressure exerted by the spring 58.

In Fig. 2 the valve member is illustrated as being in its uppermost position to which it is forced when valve 51 is open and air pressure is built upin the space 55. In this position the upper end of the member 52 engages the left end of the lever 29, the position of which is regulated by the cam 39. In this upper position of the valve member 52, the reduced portion 53 connects conduit 50 to atmosphere. This connection is from.

the conduit 50 through the space between the wall of the casing 5| and the reduced portion 53. An enlargement of the upper end of the bore in casing 5| is provided to complete the channel to atmosphere, allowing air to escape under the enlarged head of the valve member52 above the reduced portion 53.

During the initial movement of member 52, from its position shown in- Fig. 1 to the position shown in Fig. 2, the reduced portion 53 will at one instance establish the connection between the channel 55 and the conduit 69. This initial movement, due to the opening of valve 51 is, however, practically instantaneous and therefore the air permitted to flow between the channel and the conduit is of such small quantity that no actuation of the valve 42 is obtained. Its subsequent movements are under control of the left-hand end of the lever 29, which is fulcrumed on its eccentric 35 located between the pump mechanism and itsstarting'mechanism.

The operation of the starting mechanism is as follows: The left-hand end of the lever 29 is pressed downward by turning the maneuvering shaft 38 with the cam 39 in the direction of the arrow, to the effect that the length of the pump stroke is decreased or, from another viewpoint, the

clearance between the roller l8 and the cam I4 is 5 increased, or, from still another angle, a considerable portion of the pump-actuating cam I4 is rendered ineffective. The result is that a part of the normal suction stroke, as well as a part of the compression stroke of the pump plunger, are eliminated. This is important because no actuation of the suction valve 24 should take place during the starting of the engine.v In addition, the

partial elimination of the compression stroke effects opening of the relief valveas soon as the pump piston moves upward during the starting ,of the engine owing to the fact that the counterclockwise turning of the lever 29 by the maneuvering shaft 38 has substantially eliminated the lost motion between the lever 29 and the relief valve 21. No compression in the chamber 2| takes place during the starting because this chamber during the upward movement of the pump plunger is in constant communication with the discharge conduit 28. This is further important because it prevents opening of the valve connecting the chamber 2| with the conduit 23. Thus, broadly speaking, the maneuvering shaft 38 with the cam 39, together with the lever 29, form a means for rendering the pump ineffective during starting operation as far as the fuel supply to the engine cylinder is concerned. On the other hand, the pump plunger, more specifically the block 16, actuated by the cam l4 together with the lever 29 form a means for operating the starting valve of the engine as will be seen from the following: During the starting operation, the valve 51 is opened whereby actuating fluid, such as compressed air, is supplied to the space 56 and the channel 55 of the starting valve. The air pressure acting on the lower end of the valve member or piston 52 forces the piston upward against the biasing force of the spring 58, until the upper end of the member engages the left-hand end of the lever 29 and assumes the position illustrated in Fig. 2. In this position of the valve member 52, conduit 60 is connected to atmosphere, as above explained. When the left-hand end of this lever reaches its lowermost position, as illustrated in Fig. 3, the pilot valve member 52-assumes a position ,wherein the reduced portion 53 effects through the conduit 60 and the channel 55 communication of the space 56 of the auxiliary or pilot valve with the space 49a in the main valve. The air pressure inspace 49a in turn acts on piston 45 and forces it downward, resulting in opening of the valve 42 and the supply of com-- pressed air to the cylinder through the conduit or channel 43. The valve 52 is then in an intermediate position. The air pressure in the cylinder l9 moves the piston ll downward and causes in a well known manner turning of the crank shaft, not shown, and turning of the cam shaft l5 driven from the crank shaft. The latter effects downward movement of the block 16 under action of the spring l9 and accordingly upward movement of the left-hand end of lever 29. The auxiliary valve member 52 thereby is forced upward to disconnect the chamber 49a from the source of air supply and toiconnect it to atmosphere as illustrated in Fig. 2. This permits the main valve 42 to close under action of its biasing spring 41. The compressed air in the cylinder may be discharged into the atmosphere in the well manner. for instance, through a 1 charge valve which has not been shown because it forms no part of the invention. This starting operation is continued until the engine assumes the desired speed at which the valve 51 is shut off, the maneuvering shaft turned back into the 5 position shown in the drawings, and combustible fuel supplied to the cylinder.

With my invention I have accomplished an improved construction and arrangement for internal combustion engines which permits a more 10 I compact design of these engines, a simple and reliable control and operation of the fuel supply means and an effective starting operation of the engine.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In an internal combustion engine, the combination of a cylinder, a cam shaft, means including a pump having a plunger provided with a slot operated by the cam shaft for supplying fuel to the cylinder, a regulating shaft, a lever having an eccentric on the regulating shaft and one end entering said slot in the plunger, a relief and a suction valve for the pump, one of said valves being connected to the lever, and means for starting the engine including a maneuvering shaft for limiting the movement of the lever, and means operated by the lever for supplying compressed 35 air to the cylinder.

2. In an internal combustion engine, the combination of a cylinder, a cam shaft, means including a pump having a plunger with a slot operated by the cam shaft for supplying fuel to the cylinder, a valve for fixing the injection stroke of the pump, said injection stroke being effective only during the time said stroke fixing valve is closed, means for operating and adjusting the valve comprising a shaft, an eccentric on the shaft and a lever turning about the eccentric and projecting into the shaft of the plunger, and means for starting the engine comprising a main valve for ,controlling the supply of compressed air to the ing a pump having a piston operated by the cam shaft for supplying fuel to the cylinder, valve means-operable during a part of the pump stroke to' by-pass the fuel and thereby make ineffective a part of the pump stroke and means for. supplying-compressed air to the cylinder to start the engine comprising a fulcrumed lever moved by the said pump piston and a maneuvering shaft for limiting the movement of the lever to eliminate a part of the suction and the compression stroke of the pump whereby substantially no fuel operated by a member of the last named means for limiting the piston stroke for supplying compressed air to the cylinder to start the engine.

5.v In an internal combustion engine, the com- 5 bination of a cylinder, a cam shaft, means including a pump having a piston operated by the cam shaft for supplying fuel to the cylinder, valve means for limiting the supply of fuel, a lever between the piston and the valve means 10 for actuating the valve means, and means including said lever and a source of compressed gas for starting the engine;

6. In an internal combustion engine, the combination of a cylinder, a cam shaft,.means in- 15 cluding a pump having a piston operated by the cam shaft for supplying fuel to the cylinder, valve means for limiting the supply of fuel, a lever between the piston and the valve means for actuating the valve means, a regulating shaft 2 for the lever, and means including said lever and a source of compressed gas for starting the engine.

7. In an internal combustion engine, the combination of a cylinder, a cam shaft, means including a pump having a piston operated by the cam shaft for supplying fuel to the cylinder, valve means for limiting the supply of fuel, a starting mechanism, a lever fulcrumed between the cam shaft andthe starting mechanism operable by said pump piston for actuating the valve means and the said starting mechanism.

8. In an internal combustion engine, the combination of a cylinder, a cam shaft, means including a pump having a piston operated by the cam shaft for supplying fuel to the cylinder, valve means for limiting the supply of fuel, a starting mechanism, a lever fulcrumed between the valve means and said starting mechanism operable by said piston for actuating the valve means and said starting mechanism, and a regulating shaft for said lever.

ALFRED RENNER. i 

